MET antibodies are therapeutic or diagnostic agents targeting the MET receptor, a tyrosine kinase receptor encoded by the *MET* proto-oncogene. MET, also known as hepatocyte growth factor (HGF) receptor, plays a critical role in embryogenesis, tissue repair, and cancer progression by regulating cell proliferation, survival, motility, and angiogenesis. Aberrant MET signaling, caused by gene amplification, mutations, or HGF overexpression, is implicated in tumor growth, metastasis, and resistance to therapies in various cancers, including lung, gastric, and hepatocellular carcinomas.
Therapeutic MET antibodies are designed to block HGF binding or receptor dimerization, inhibiting downstream signaling. Examples include monovalent monoclonal antibodies (e.g., onartuzumab) and bivalent antibodies (e.g., emibetuzumab). While early clinical trials showed mixed results—onartuzumab failed in phase III trials for non-small cell lung cancer (NSCLC)—renewed interest focuses on patient stratification using biomarkers (e.g., *MET* amplification/exon 14 skipping) and combination therapies. Bispecific antibodies targeting MET alongside other receptors (e.g., EGFR or VEGF) aim to enhance efficacy and overcome resistance.
Diagnostic MET antibodies aid in detecting MET overexpression or activation in tumors, guiding targeted therapy decisions. Challenges include tumor heterogeneity, limited predictive biomarkers, and compensatory signaling. Ongoing research explores next-generation antibodies, antibody-drug conjugates, and immunotherapies to optimize MET-targeted strategies in precision oncology.